tissue. In response to insulin, GLUT translocates from Dub inhibitor the cytoplasm to the cell membrane and mediates the transport of glucose. Zisman et al. reported that mice carrying a muscle specific deletion of the GLUT gene developed severe insulin resistance and glucose intolerance. A study using adipose specific GLUT knockout mouse models also showed that these mice developed insulin resistance and glucose intolerance . These results demonstrate that GLUT has an essential role in the maintenance of normal glucose homeostasis. In this study,we induced insulin resistance in rats by feeding thema high fat diet and measured the expression of the ATM protein and the phosphorylation of Akt in their skeletal muscle tissue. The functional link between ATMand Akt was further examined in MEF A and A cells.
In addition, the effect of ATM on Akt phosphorylation following insulin treatment in L muscle cells was studied using a specific inhibitor of ATM. We also conducted experiments to see if there is a functional Dub inhibitor connection between the ATMprotein kinase and the translocation of GLUT in response to insulin in L cells Materials and methods Materials The antibody against tubulin was from Sigma. The anti c myc antibody was from Santa Cruz. The Cy conjugated goat anti mouse antibody was from Jackson Immuno Research Laboratories. The antibodies against phospho Ser and phospho Thr of Akt, as well as the antibodies against the different Akt isoforms were from Cell Signaling Technology. The antibodies against total Akt, phospho c Jun, and total c Jun were from Santa Cruz Biotechnology.
The antibodies against phospho Tyr of insulin receptor substrate or Dasatinib total IRS were from Biosource and Upstate, respectively. The antibody against phospho tyrosine was from Cell Signaling. The anti ATM monoclonal antibodyMATwas a generous gift fromDr. Yossi Shiloh . The Effectene transfection reagentwas from Qiagen. H deoxyglucose was purchased from Perkin Elmer. The plasmid encoding FLAG tagged wild type or kinase dead ATM protein was provided by Dr. Michael B. Kastan . Rats with insulin resistance Male Wistar rats were used at weeks of age. All animalswere pair housed at TheUniversity of South Dakota's Laboratory Animal Services facilitywhere they received food and water ad libitum and a : light dark photoperiod.
All animal procedureswere performed under a protocol reviewed and approved PARP by The University of South Dakota InstitutionalAnimalCare andUse Committee andwere in accordancewith theNIH guidelines. These ratswere inducedwith insulin resistance through the administration of a high fat diet , which contained . kcal g. Approximately of the total calories in the diet came fromlard. This Teklad diet was originally formulated as a version of the Bio Serv diet F, which has been used to successfully induce insulin resistance and or obesity in rodents . Control rats were given standard rodent chow . Glucose and insulin measurement Levels of glucose were measured on a weekly basis using Dasatinib a hand held glucometer . Blood was collected for weekly glucose monitoring via tail vein puncture. Periodically throughout the study , blood was collected for the insulin assay via jugular puncture.
Blood samples were centrifuged, and serum was frozen at ? C. Insulin levels were analyzed with an ELISA kit using rat insulin as a standard. All blood collection involved overnight fasting of the animals. Measurement of Deubiquitinase inhibitor insulin resistance Insulin resistance was determined by the Quantitative Insulin Sensitivity Check Index method. The QUICKI is defined as where I is the insulin level as U mL and G is the glucose level as mg dL. Muscle tissue collection and homogenization After months on the high fat diet, both high fat rats and control rats were anesthetized Dasatinib via continuous isoflurane inhalation and the gastrocnemius muscle was excised from the animals. All muscle tissue was quickly weighed, rinsed with PBS, and snap frozen in liquid nitrogen .
Animals were ultimately killed via cervical dislocation, and all tissuewas stored at ? C. Muscle tissuewas ground and powdered using a mortar pestle with continuous liquid nitrogen application. The samples were then homogenized in homogenization buffer containing mM Tris HCl, Dasatinib mM EDTA, mM NaCl, Triton X , and mM each of PMSF, NaF, NaVO, plus protease inhibitor cocktail tablets . The resulting homogenate was stored at ? C. insulin resistance in rats by feeding them a high fat diet. This is an establishedmethod and is based onprevious studies performed inmany other laboratories . Control rats were given standard rodent chow. Insulin resistance was determined by the QUICKI method. The QUICKI method is a mathematical model that has been found to correlate well with the gold standard in insulin resistance assays, the euglycemic clamp . Insulin resistant animals tend to have lower QUICKI or insulin sensitivity values. After to months on the high fat diet, these rats exhibited a significant increase in insulin levels over the control rats. A signi
Thursday, July 25, 2013
New Dub inhibitor Dasatinib Is Twice The Fun
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